1. Field of the Invention
The present invention relates to an optical system. More particularly, the present invention relates to an optical system.
2. Description of Related Art
As electronic products have a general trend of miniaturization and low price, a wafer level module (WLM) technique is disclosed. The WLM technique is mainly to fabricate the electronic product according to a wafer level fabrication technique, so as to miniaturize a size of the electronic product and reduce a cost thereof. Wherein, the WLM technique can also be applied for fabricating an optical system, so that a size of the optical system can be reduced compared to that of a conventional optical system, and accordingly the miniaturized optical system can be applied to, for example, a camera module of a mobile phone.
FIG. 1 is a schematic diagram of a conventional optical system. Referring to FIG. 1, the optical system 100 includes a photo sensor 110, an optical lens 120 and a focusing motor 130. The focusing motor 130 is located on the photo sensor 110. The optical lens 120 is located in the focusing motor 130, and the focusing motor 130 is adapted to control a relative movement of the optical lens 120, so as to drive the optical lens 120 to move toward or backward the photo sensor 110.
In the optical system 100, the optical lens 120 includes two transparent substrates 122 and a plurality of lenses 124 located on the transparent substrates 122. The focusing motor 130 includes a telescopic structure 132, wherein the telescopic structure 132 is inlaid to the optical lens 120, so that when the telescopic structure 132 is driven by the focusing motor 130, it can control the optical lens 120 to move toward or backward the photo sensor 110.
The optical lens 120 is located in the focusing motor 130, and the focusing motor 130 can drive the optical lens 120 to move toward or backward the photo sensor 110 through the telescopic structure 132 inlaid to the optical lens 120. However, a whole size of the optical system 100 cannot be effectively reduced due to such a structure, so that miniaturization of the whole size is hard to be achieved.